FastAPI Release Notes
Last updated: Mar 2, 2026
- Mar 1, 2026
- Date parsed from source:Mar 1, 2026
- First seen by Releasebot:Mar 2, 2026
0.135.1
Fixes
- š Fix, avoid yield from a TaskGroup, only as an async context manager, closed in the request async exit stack. PR #15038 by @tiangolo.
Docs
- āļø Fix typo in docs/en/docs/_llm-test.md. PR #15007 by @adityagiri3600.
- š Update Skill, optimize context, trim and refactor into references. PR #15031 by @tiangolo.
Internal
- š„ Update FastAPI People - Experts. PR #15037 by @tiangolo.
- š„ Update FastAPI People - Contributors and Translators. PR #15029 by @tiangolo.
- š„ Update FastAPI GitHub topic repositories. PR #15036 by @tiangolo.
- Mar 1, 2026
- Date parsed from source:Mar 1, 2026
- First seen by Releasebot:Mar 2, 2026
0.135.0
Features
āØ Add support for Server Sent Events. PR #15030 by @tiangolo.
New docs: Server-Sent Events (SSE).
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- Feb 27, 2026
- Date parsed from source:Feb 27, 2026
- First seen by Releasebot:Feb 28, 2026
0.134.0
New streaming features arrive: JSON Lines and binary data with yield, and a Starlette upgrade for proper exception handling. Includes new streaming docs (Stream JSON Lines, Stream Data) and code examples, plus test and doc sanity updates.
Features
- āØ Add support for streaming JSON Lines and binary data with yield. PR #15022 by @tiangolo.
- This also upgrades Starlette from >0.40.0 to >0.46.0, as it's needed to properly unrwap and re-raise exceptions from exception groups.
- New docs: Stream JSON Lines.
- And new docs: Stream Data.
Docs
- š Update Library Agent Skill with streaming responses. PR #15024 by @tiangolo.
- š Update docs for responses and new stream with yield. PR #15023 by @tiangolo.
- š Add await in StreamingResponse code example to allow cancellation. PR #14681 by @casperdcl.
- š Rename docs_src/websockets to docs_src/websockets_ to avoid import errors. PR #14979 by @YuriiMotov.
Internal
- šØ Run tests with pytest-xdist and pytest-cov. PR #14992 by @YuriiMotov.
- Feb 25, 2026
- Date parsed from source:Feb 25, 2026
- First seen by Releasebot:Feb 25, 2026
0.133.1
Features
- š§ Add FastAPI Agent Skill. PR #14982 by @tiangolo.
- Read more about it in Library Agent Skills.
Internal
- ā Fix all tests are skipped on Windows. PR #14994 by @YuriiMotov.
- Feb 24, 2026
- Date parsed from source:Feb 24, 2026
- First seen by Releasebot:Feb 25, 2026
0.133.0
Upgrades
ā¬ļø Add support for Starlette 1.0.0+. PR #14987 by @tiangolo.
Original source Report a problem - Feb 23, 2026
- Date parsed from source:Feb 23, 2026
- First seen by Releasebot:Feb 24, 2026
0.132.0
FastAPI now enforces valid JSON Content-Type headers by default, with an opt-out. It also updates Flask, griffelib, and related tooling, plus workflow and coverage tweaks to speed up processing.
Breaking Changes
- šļø Add strict_content_type checking for JSON requests. PR #14978 by @tiangolo.
Now FastAPI checks, by default, that JSON requests have a Content-Type header with a valid JSON value, like application/json, and rejects requests that don't.
If the clients for your app don't send a valid Content-Type header you can disable this with strict_content_type=False.
Check the new docs: Strict Content-Type Checking.
Internal
- ā¬ Bump flask from 3.1.2 to 3.1.3. PR #14949 by @dependabot[bot].
- ā¬ Update all dependencies to use griffelib instead of griffe. PR #14973 by @svlandeg.
- šØ Fix FastAPI People workflow. PR #14951 by @YuriiMotov.
- š· Do not run codspeed with coverage as it's not tracked. PR #14966 by @tiangolo.
- š· Do not include benchmark tests in coverage to speed up coverage processing. PR #14965 by @tiangolo.
- Feb 22, 2026
- Date parsed from source:Feb 22, 2026
- First seen by Releasebot:Feb 23, 2026
0.131.0
Breaking Changes
šļø Deprecate ORJSONResponse and UJSONResponse. PR #14964 by @tiangolo.
Original source Report a problem - Feb 22, 2026
- Date parsed from source:Feb 22, 2026
- First seen by Releasebot:Feb 23, 2026
0.130.0
Features
- āØ Serialize JSON response with Pydantic (in Rust), when there's a Pydantic return type or response model. PR #14962 by @tiangolo.
- This results in 2x (or more) performance increase for JSON responses.
- New docs: Custom Response - JSON Performance.
- Feb 21, 2026
- Date parsed from source:Feb 21, 2026
- First seen by Releasebot:Feb 22, 2026
0.129.2
Internal
- ā¬ļø Upgrade pytest. PR #14959 by @tiangolo.
- š· Fix CI, do not attempt to publish fastapi-slim. PR #14958 by @tiangolo.
- ā Drop support for fastapi-slim, no more versions will be released, use only "fastapi[standard]" or fastapi. PR #14957 by @tiangolo.
- š§ Update pyproject.toml, remove unneeded lines. PR #14956 by @tiangolo.
- Feb 21, 2026
- Date parsed from source:Feb 21, 2026
- First seen by Releasebot:Feb 21, 2026
0.129.1
A fresh release brings fixes to JSON Schema, a new Kapa.ai widget, translation updates across many languages, and docs improvements. It also cleans up Python 3.9 files and bumps dependencies while tightening JWT timing protections.
Fixes
- ā»ļø Fix JSON Schema for bytes, use "contentMediaType": "application/octet-stream" instead of "format": "binary". PR #14953 by @tiangolo.
Docs
- šØ Add Kapa.ai widget (AI chatbot). PR #14938 by @tiangolo.
- š„ Remove Python 3.9 specific files, no longer needed after updating translations. PR #14931 by @tiangolo.
- š Update docs for JWT to prevent timing attacks. PR #14908 by @tiangolo.
Translations
- āļø Fix several typos in ru translations. PR #14934 by @argoarsiks.
- š Update translations for ko (update-all and add-missing). PR #14923 by @YuriiMotov.
- š Update translations for uk (add-missing). PR #14922 by @YuriiMotov.
- š Update translations for zh-hant (update-all and add-missing). PR #14921 by @YuriiMotov.
- š Update translations for fr (update-all and add-missing). PR #14920 by @YuriiMotov.
- š Update translations for de (update-all) . PR #14910 by @YuriiMotov.
- š Update translations for ja (update-all). PR #14916 by @YuriiMotov.
- š Update translations for pt (update-all). PR #14912 by @YuriiMotov.
- š Update translations for es (update-all and add-missing). PR #14911 by @YuriiMotov.
- š Update translations for zh (update-all). PR #14917 by @YuriiMotov.
- š Update translations for uk (update-all). PR #14914 by @YuriiMotov.
- š Update translations for tr (update-all). PR #14913 by @YuriiMotov.
- š Update translations for ru (update-outdated). PR #14909 by @YuriiMotov.
Internal
- š· Always run tests on push to master branch and when run by scheduler. PR #14940 by @YuriiMotov.
- šØ Upgrade typing syntax for Python 3.10. PR #14932 by @tiangolo.
- ā¬ Bump cryptography from 46.0.4 to 46.0.5. PR #14892 by @dependabot[bot].
- ā¬ Bump pillow from 12.1.0 to 12.1.1. PR #14899 by @dependabot[bot].